Editor’s Note: The Engineerist is a three-part blog series written by Michael Corr, founder of Los Angeles-based manufacturing consulting firm, DuroLabs. This is part two.
Certification testing is expensive, especially when your product fails.
I was managing an engineering team several years ago when we submitted a new product with an injection-molded enclosure to UL for certification testing. The tests included a mechanical stress test with some rather extreme impact forces. This product was a deviation to a predecessor and therefore had legacy requirements which constrained our design options. With the time pressure we had to get the product to market, the mechanical engineering team and I were hoping a few modest changes to the existing legacy injection mold would be sufficient to pass the new certification testing and go into production. They weren’t.
Logo Image: PR Newswire
Prototype Prep Before UL Testing
After a humbling blow to our egos and sizeable invoices from both the molder and UL, we took another approach. The ME team reviewed the points of failure of the plastic enclosure and came up with a few design improvements. But we didn’t want to risk failure again, and UL required testing parts fabricated from the actual production mold. It would be too expensive and risky if we were to modify the tool and fail again. Continue reading
University of Minnesota engineering students are readying a 3D-printed rocket engine for launch sometime later this year, with help from Proto Labs.
This cutaway view of the engine shows the cooling channel, which is one long tube that spirals down inside the wall.
David Deng, a senior aerospace engineering student at the U of M’s Twin Cities campus, is leading the extracurricular effort to design, build, and eventually fly a liquid-propellant rocket as project manager of LPRD Rocketry. The group’s name, pronounced “leopard,” is an acronym for Liquid Propellant Rocketry Design. The group includes aerospace engineering students and others studying electrical engineering, computer science, mechanical engineering, and materials science.
The primary design challenges the group faced included the small overall size of the engine itself, and the need to also somehow incorporate a cooling system inside the engine.
David Deng (right), and the University of Minnesota student group LPRD Rocketry (left).
“The manufacturing of [the rocket engine] is incredibly difficult using conventional methods, especially for a very small engine,” Deng said. “The struggle was how do we [add] a single cooling channel through this entire engine, coiling around the side of it? That’s where Proto Labs came in. 3D printing is essentially the only way to get regenerative cooling on an engine this small and have it be a single channel.”
READ CASE STUDY
The drone market in the U.S. is expected to soar to an $82-billion industry in the next decade, the New York Times recently reported. With that robust market in mind, Lockheed Martin, the aerospace, defense, and technology giant, developed a small, fold-up, lightweight drone, the Indago Quadcopter UAV (unmanned aerial vehicle), turning to Proto Labs for quick-turn prototyping and low-volume production.
Proto Labs’ automated design for manufacturability (DFM) and quoting system was especially helpful in taking the Indago from 3D-printed prototypes to injection-molded parts, and getting finished parts delivered in days and weeks. The video tells the story:
Injection molding is a common, cost-effective method for manufacturing parts, but, sometimes, those parts need a little help. Low impact or vibration resistance, slippery surfaces, poor ergonomics, and cosmetic concerns are only a few of the reasons why a second molded part is often added as a grip, handle, cover, or sleeve.
Proto Labs now offers rapid overmolding for parts, including the three samples pictured here.
The process of rapid overmolding will get the job done. This method, which Proto Labs now offers, and is the focus of our October design tip, uses a mechanical or chemical bond (or both) to permanently marry two parts together.
This month’s tip discusses:
- Bonding: A strong bond between the two materials is critical to overmolding.
- Materials: This is a key consideration in overmolding.
- Principles: Overmolding uses the same playbook as injection molding, but with a few quirks.
READ FULL DESIGN TIP
3D printing is the topic of conversation in our latest Journal issue, which focuses on the technology’s next dimension—how additive manufacturing is poised to make a giant leap forward in capabilities.
The cover story includes interviews with three leaders from the 3D printing industry who offer insight on a variety of topics, such as advancements in new machines and materials, a growing demand for 3D printing for production parts, and notable trends in software.
Another feature, “A Cloud-Based Future for CAD,” explores how 3D CAD design software is increasingly moving to cloud-based models, a trend with benefits for both product developers and manufacturers.
Elsewhere in the Journal, our Eye on Innovation column features a driverless bus, a 3D GoPro, and a DIY Bluetooth.
Read the entire Journal here.
We’re always on the hunt for though-provoking content, so send your cool project or article idea to our editor at email@example.com.
Thanks and enjoy the issue!